The present invention relates generally to user-actuated navigation of a document using a data processing apparatus. More particularly, the invention relates to enhancing electronic scrolling of a document through use of a cursor control device.
The computer mouse has simplified the computer-human interface. Before the computer mouse, many users were confined to interacting with a computer through the use of a command line interface (CLI as is known in the art). The computer mouse (also commonly referred to simply as a “mouse”) has, in recent years, been improved upon with the inclusion of a wheel on the top of the mouse. An example of a wheeled mouse is shown in FIG. 1. The function of the wheel 106 is to scroll the text or document or image located below a displayed cursor 113 shown on a visual display device 112. The wheel is linked to an optically encoded wheel for sensing the rotational location of the wheel 106. To allow for feedback to the user, the wheel contains a number of notches (not shown for simplicity). When rotated, a user is presented with tactile feedback of the distance rotated through sensing the number of notches rotated by the wheel. The function of wheel 106 is interpreted through signals sent from mouse 101 through a cable 110 to a computer 109 having a memory 114 and a processor 115. Shown for completeness is a keyboard 116, which is generally used in combination with mouse 101 for various operations as are known in the art. For example, rotating the wheel away from the user may scroll the underlying displayed content down so as to show another portion of the displayed content immediately preceding the originally displayed content. Likewise, rotating the wheel toward the user may scroll the underlying displayed content up.
Other features of a wheeled mouse and alternative techniques of navigating a display through the use of the wheeled mouse are disclosed in U.S. Ser. No. 09/212,898, filed Dec. 16, 1998, for “System and Method of Adjusting Display Characteristics of a Displayable Data File Using An Ergonomic Computer Input Device.” The contents of this application are hereby incorporated by reference herein.
When a user desires to move long distances through a document displayed on a computer, various methods can be used. Using a typical computer keyboard, the user can use cursor arrows or page up and page down keys. Referring to FIG. 2, a GUI of a known word processing application shown an exemplary display window 200. Associated with window 200 are a vertical scroll bar 202 and a horizontal scroll bar 204. On each scroll bar 202, 204 there is a thumb 206, 208, an associated trough 210, 212, and a pair of navigation arrows (214a, 214b), (216a, 216b). Using a mouse or other conventional input device, e.g., trackball or touch pad, a user can interact in various ways with the scroll bars 202, 204. However, the use of scroll bars can be time consuming and distracting. The user must divert his/her attention away from the open document while an element of the scroll bar is acquired. As the user scrolls, the user must continuously divide his/her attention between the document and the scroll bar itself. In addition, some users may consider conventional scroll bars to be overly complicated, by virtue of the three different scrolling functionality elements utilized. The thumb 206, 208 of the scroll bar may be dragged in order to move quickly from one end of the document to the other. The navigation arrows (214a, 214b), (216a, 216b) may be clicked in order to move one line at a time. The trough 210, 212 of the scroll bar may be clicked in order to scroll up or down one screen at a time.
Scrolling through a computer document using wheel 106 on wheeled computer mouse 101 is helpful in that it provides useful document handling without the need to access the keyboard or displayed scroll bars. In a known wheel scrolling system, for every notch indent of rotation of the wheel, the screen display may scroll only one line. While this is effective for scrolling short distances, it is tedious and time consuming for scrolling longer distances.
A known “rate based” (position-rate mapping) scrolling system uses a mouse wheel or other button for scrolling through a displayed computer document. When the user clicks the wheel button and then drags the mouse, scrolling is carried out at a speed (rate) proportional to the displacement of the mouse from the point where the dragging motion was initiated. The scrolling continues until the user clicks the mouse wheel a second time. Alternatively, rate-based scrolling occurs while the wheel is clicked and held, until released. Many users find that precision scrolling is difficult with this “rate based” scrolling control. Studies have shown rate based scrolling as implemented with a mouse to be non-intuitive and slower as compared with other known cursor control schemes.
Some computer applications, such as Adobe Acrobat Reader®, employ a technique that allow the user to “grab” a document with the mouse and move the document in relation to the movement of the mouse. This technique has a number of drawbacks. The grabbing technique moves the document in the same direction as the mouse is moved, which is inconsistent with the use of the scroll bar and thus potentially confusing to users. Also, while the grabbing is being performed, the mouse cursor is visible and limited in movement by the edges of the display window. Grabbing may be an optional mode of an application. Thus, the user may be required to click on a menu button to activate the grabbing mode, which takes the user's attention away from the open document. Likewise, if the user has activated another mode, such as zooming, then grabbing is no longer available unless the user again activates a menu button to switch modes. Additionally, the grabbing functionality is implemented by specific applications and is not performed system wide. Also the grabbing mode offered in applications, such as Adobe, allows the user only to scroll within a displayed page; the mode is thus cumbersome and inappropriate for scrolling through multiple pages.
A less time consuming, less distracting and less complicated system for electronic scrolling of documents would represent a significant advancement in the art, as would a more accurate system for scrolling that is easier to control and which combines multiple functional modes for scrolling both long and short distances.